Well, perfectly normal human beings who should be dead where they came from are very much alive here, is all.

[HA HA, BUT ENOUGH OF THAT, HOW ABOUT THAT OTHER TOPIC.]

But as for ghost type Pokemon--! They seem to be a topic of serious interest debate in the field of Pokemon research, from what I've read! They can be lay eggs that hatch into other ghost types, yet they can also be the 'afterlife' stage of what was formerly a different kind of Pokemon entirely! Something like that is incredibly strange, if you ask me!